package org.express.portal.persist;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.beanutils.BeanUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DBManager
{
	private static final Logger log = LoggerFactory.getLogger(DBManager.class);
	private final static ThreadLocal<Connection> conns = new ThreadLocal<Connection>();
	private static DataSource dataSource;
	private static boolean show_sql = false;

	static
	{
		initDataSource(null);
	}

	/**
	 * 初始化连接
	 * 
	 * @param dbProperties
	 */
	private final static void initDataSource(Properties dbProperties)
	{
		try
		{
			if (dbProperties == null)
			{
				dbProperties = new Properties();
				dbProperties.load(DBManager.class.getResourceAsStream("/config/jdbc.properties"));
			}
			Properties cp_props = new Properties();
			for (Object key : dbProperties.keySet())
			{
				String skey = (String) key;
				if (skey.startsWith("jdbc."))
				{
					String name = skey.substring(5);
					cp_props.put(name, dbProperties.getProperty(skey));
					if ("show_sql".equalsIgnoreCase(name))
					{
						show_sql = "true".equalsIgnoreCase(dbProperties.getProperty(skey));
					}
				}
			}
			dataSource = (DataSource) Class.forName(cp_props.getProperty("dataSource")).newInstance();
			if (dataSource.getClass().getName().indexOf("c3p0") > 0)
			{
				// Disable JMX in C3P0
				System.setProperty("com.mchange.v2.c3p0.management.ManagementCoordinator", "com.mchange.v2.c3p0.management.NullManagementCoordinator");
			}
			log.info("Using DataSource : " + dataSource.getClass().getName());
			BeanUtils.populate(dataSource, cp_props);

			Connection conn = getConnection();
			DatabaseMetaData mdm = conn.getMetaData();
			log.info("Connected to " + mdm.getDatabaseProductName() + " " + mdm.getDatabaseProductVersion());
			closeConnection();
		}
		catch (Exception e)
		{
			log.error(e.getMessage());
		}
	}

	/**
	 * 断开连接池
	 */
	public final static void closeDataSource()
	{
		try
		{
			dataSource.getClass().getMethod("close").invoke(dataSource);
		}
		catch (NoSuchMethodException e)
		{
		}
		catch (Exception e)
		{
			log.error("Unabled to destroy DataSource!!! ", e);
		}
	}

	public final static Connection getConnection() throws SQLException
	{
		Connection conn = conns.get();
		if (conn == null || conn.isClosed())
		{
			conn = dataSource.getConnection();
			conns.set(conn);
		}
		return (show_sql && !Proxy.isProxyClass(conn.getClass())) ? new _DebugConnection(conn).getConnection() : conn;
	}

	/**
	 * 关闭连接
	 */
	public final static void closeConnection()
	{
		Connection conn = conns.get();
		try
		{
			if (conn != null && !conn.isClosed())
			{
				conn.setAutoCommit(true);
				conn.close();
			}
		}
		catch (SQLException e)
		{
			log.error("Unabled to close connection!!! ", e);
		}
		conns.set(null);
	}

	static class _DebugConnection implements InvocationHandler
	{
		private final static Logger log = LoggerFactory.getLogger(_DebugConnection.class);
		private Connection conn = null;

		public _DebugConnection(Connection conn)
		{
			this.conn = conn;
		}

		/**
		 * Returns the conn.
		 * 
		 * @return Connection
		 */
		public Connection getConnection()
		{
			return (Connection) Proxy.newProxyInstance(conn.getClass().getClassLoader(), conn.getClass().getInterfaces(), this);
		}

		public Object invoke(Object proxy, Method m, Object[] args) throws Throwable
		{
			try
			{
				String method = m.getName();
				if ("prepareStatement".equals(method) || "createStatement".equals(method))
					log.info("[SQL] >>> " + args[0]);
				return m.invoke(conn, args);
			}
			catch (InvocationTargetException e)
			{
				throw e.getTargetException();
			}
		}
	}
}
